Abstract
This spectroscopic coincidence is considered from the viewpoint of experiments to measure tetrahedral parameters applicable to extensive calculations of atmospheric spectra. Theoretical results related to the polar character of the ground and excited vibrational states are discussed. Numerical values for ground‐state transition frequencies, and estimates for ground‐ and excited‐state Stark shifts, are given for the R (6) multiplet in 2ν3 of 12CH4. Possible applications are mentioned for 13CH4.